$\"\"$ $\"\"$ $\"\"$

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The expression is $\"\"$ . \ \

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According to subtraction property of equality: if $\"\"$ , then $\"\"$ .

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$\"\"$ (Subtract 30 from each side)

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$\"\"$ (Additive identity property: $\"\"$ )

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$\"\"$ (Additive inverse property: $\"\"$ )

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$\"\"$

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According to Multiplication property of equality: if $\"\"$ , then $\"\"$ .

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$\"\"$ (Multiply each side by 3)

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$\"\"$ (Cancel common terms)

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$\"\"$ (Multiply: $\"\"$ )

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According to division property of equality: if $\"\"$ , then $\"\"$ .

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$\"\"$ (Divide each side by 2)

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$\"\"$ (Cancel common terms)

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$\"\"$ (Divide: $\"\"$ )

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$\"\"$ (Take square roots of each side)

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$\"\"$

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$\"\"$

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$\"\"$

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Product property of square roots:

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For nonnegative real numbers a and b, $\"\"$

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$\"\"$

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$\"\"$

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Rewrite the (-1) using imaginary unit; that is $\"\"$ where i² = -1.

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$\"\"$ \ \

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$\"\"$ (Find the square root: $\"\"$ )

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$\"\"$ (Simplify) $\"\"$

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The value of x $\"\"$ .